We have investigated reports of a spoofing vulnerability in AppX installer that affects Microsoft Windows. Microsoft is aware of attacks that attempt to exploit this vulnerability by using specially crafted packages that include the malware family known as Emotet/Trickbot/Bazaloader.
An attacker could craft a malicious attachment to be used in phishing campaigns. The attacker would then have to convince the user to open the specially crafted attachment. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights.
Please see the Security Updates table for the link to the updated app. Alternatively you can download and install the Installer using the links provided in the FAQ section.
Please see the Mitigations and Workaround sections for important information about steps you can take to protect your system from this vulnerability.
December 27 2023 Update:
In recent months, Microsoft Threat Intelligence has seen an increase in activity from threat actors leveraging social engineering and phishing techniques to target Windows OS users and utilizing the ms-appinstaller URI scheme.
To address this increase in activity, we have updated the App Installer to disable the ms-appinstaller protocol by default and recommend other potential mitigations.
References
| Link | Resource |
|---|---|
| https://github.com/ChrisTitusTech/winutil/pull/26 | Issue Tracking |
| https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43890 | Patch Vendor Advisory |
| https://thehackernews.com/2023/12/microsoft-disables-msix-app-installer.html | Press/Media Coverage Third Party Advisory |
| https://www.bleepingcomputer.com/news/microsoft/microsoft-disables-msix-protocol-handler-abused-in-malware-attacks/ | Press/Media Coverage Third Party Advisory |
| https://www.microsoft.com/en-us/security/blog/2023/12/28/financially-motivated-threat-actors-misusing-app-installer/ | Exploit Vendor Advisory |
Configurations
Configuration 1 (hide)
| AND |
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Configuration 2 (hide)
| AND |
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History
24 Jul 2024, 16:52
| Type | Values Removed | Values Added |
|---|---|---|
| CPE | cpe:2.3:o:microsoft:windows_10:-:*:*:*:*:*:x64:* |
cpe:2.3:o:microsoft:windows_10_1909:-:*:*:*:*:*:*:* cpe:2.3:o:microsoft:windows_11_21h2:-:*:*:*:*:*:*:* cpe:2.3:o:microsoft:windows_10_1903:-:*:*:*:*:*:*:* cpe:2.3:o:microsoft:windows_10_1809:-:*:*:*:*:*:*:* cpe:2.3:o:microsoft:windows_10_1507:-:*:*:*:*:*:*:* cpe:2.3:o:microsoft:windows_10_2004:-:*:*:*:*:*:*:* cpe:2.3:o:microsoft:windows_10_20h2:-:*:*:*:*:*:*:* cpe:2.3:o:microsoft:windows_10_21h1:-:*:*:*:*:*:*:* cpe:2.3:o:microsoft:windows_10_1709:-:*:*:*:*:*:*:* cpe:2.3:o:microsoft:windows_10_21h2:-:*:*:*:*:*:*:* cpe:2.3:o:microsoft:windows_10_1803:-:*:*:*:*:*:*:* |
| References | () https://github.com/ChrisTitusTech/winutil/pull/26 - Issue Tracking | |
| References | () https://thehackernews.com/2023/12/microsoft-disables-msix-app-installer.html - Press/Media Coverage, Third Party Advisory | |
| References | () https://www.bleepingcomputer.com/news/microsoft/microsoft-disables-msix-protocol-handler-abused-in-malware-attacks/ - Press/Media Coverage, Third Party Advisory | |
| References | () https://www.microsoft.com/en-us/security/blog/2023/12/28/financially-motivated-threat-actors-misusing-app-installer/ - Exploit, Vendor Advisory | |
| First Time |
Microsoft windows 10 21h1
Microsoft windows 10 1909 Microsoft windows 10 1507 Microsoft windows 10 1803 Microsoft windows 10 20h2 Microsoft windows 11 21h2 Microsoft windows 10 1709 Microsoft windows 10 1809 Microsoft windows 10 1903 Microsoft windows 10 2004 Microsoft windows 10 21h2 |
29 May 2024, 15:15
| Type | Values Removed | Values Added |
|---|---|---|
| Summary | (en) We have investigated reports of a spoofing vulnerability in AppX installer that affects Microsoft Windows. Microsoft is aware of attacks that attempt to exploit this vulnerability by using specially crafted packages that include the malware family known as Emotet/Trickbot/Bazaloader. An attacker could craft a malicious attachment to be used in phishing campaigns. The attacker would then have to convince the user to open the specially crafted attachment. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. Please see the Security Updates table for the link to the updated app. Alternatively you can download and install the Installer using the links provided in the FAQ section. Please see the Mitigations and Workaround sections for important information about steps you can take to protect your system from this vulnerability. December 27 2023 Update: In recent months, Microsoft Threat Intelligence has seen an increase in activity from threat actors leveraging social engineering and phishing techniques to target Windows OS users and utilizing the ms-appinstaller URI scheme. To address this increase in activity, we have updated the App Installer to disable the ms-appinstaller protocol by default and recommend other potential mitigations. |
30 Dec 2023, 07:15
| Type | Values Removed | Values Added |
|---|---|---|
| Summary | <p>We have investigated reports of a spoofing vulnerability in AppX installer that affects Microsoft Windows. Microsoft is aware of attacks that attempt to exploit this vulnerability by using specially crafted packages that include the malware family known as Emotet/Trickbot/Bazaloader.</p> <p>An attacker could craft a malicious attachment to be used in phishing campaigns. The attacker would then have to convince the user to open the specially crafted attachment. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights.</p> <p>Please see the <strong>Security Updates</strong> table for the link to the updated app. Alternatively you can download and install the Installer using the links provided in the <strong>FAQ</strong> section.</p> <p>Please see the <strong>Mitigations</strong> and <strong>Workaround</strong> sections for important information about steps you can take to protect your system from this vulnerability.</p> <p><strong>December 27 2023 Update:</strong></p> <p>In recent months, Microsoft Threat Intelligence has seen an increase in activity from threat actors leveraging social engineering and phishing techniques to target Windows OS users and utilizing the <a href="https://learn.microsoft.com/en-us/windows/msix/app-installer/installing-windows10-apps-web">ms-appinstaller URI scheme</a>.</p> <p>To address this increase in activity, we have updated the App Installer to disable the ms-appinstaller protocol by default and recommend other potential mitigations.</p> | |
| References |
|
12 Jul 2022, 17:42
| Type | Values Removed | Values Added |
|---|---|---|
| CWE | NVD-CWE-noinfo |
23 Dec 2021, 14:23
| Type | Values Removed | Values Added |
|---|---|---|
| CWE | CWE-290 | |
| CVSS |
v2 : v3 : |
v2 : 6.0
v3 : 7.1 |
| CPE | cpe:2.3:o:microsoft:windows_10:-:*:*:*:*:*:x86:* cpe:2.3:o:microsoft:windows_10:-:*:*:*:*:*:x64:* cpe:2.3:a:microsoft:app_installer:*:*:*:*:*:*:*:* |
|
| References | (MISC) https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43890 - Patch, Vendor Advisory |
15 Dec 2021, 15:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2021-12-15 15:15
Updated : 2024-07-24 16:52
NVD link : CVE-2021-43890
Mitre link : CVE-2021-43890
CVE.ORG link : CVE-2021-43890
JSON object : View
Products Affected
microsoft
- windows_10_21h2
- windows_10_20h2
- windows_10_1709
- windows_10_1909
- windows_10_1809
- windows_10_1507
- windows_10_2004
- windows_10_21h1
- windows_11_21h2
- app_installer
- windows_10_1803
- windows_10_1903
CWE